1. Field
The present disclosure generally relates to a semiconductor chip package. More specifically, the present disclosure relates to a chip package that facilitates assembly and integration of a group of chips arranged in a stack.
2. Related Art
Chip packages that include stacked semiconductor chips can provide higher performance and lower cost in comparison to conventional individually packaged chips that are connected to a printed circuit board. These chip packages also provide certain advantages, such as the ability to: use different processes on different chips in the stack, combine higher density logic and memory, and transfer data using less power. For example, a stack of chips that implements a dynamic random access memory (DRAM) can use a high-metal-layer-count, high-performance logic process in a base chip to implement input/output (I/O) and controller functions, and a set of lower metal-layer-count, DRAM-specialized processed chips can be used for the rest of the stack. In this way the combined set of chips may have better performance and lower cost than: a single chip that includes I/O and controller functions manufactured using the DRAM process; a single chip that includes memory circuits manufactured using a logic process; and/or attempting to use a single process to make both logic and memory physical structures.
One approach for stacking chips involves a chip package in which the chips in a stack are offset from each other, thereby defining a terrace with exposed pads. A high-bandwidth ramp component, which is positioned approximately parallel to the terrace, electrically couples to the exposed pads. While the chip package can provide high inter-component communication bandwidth and high component density, it can be difficult to position the ramp component along the terrace and, thus, to fabricate the chip package. This difficulty can reduce the yield and increase the cost of the chip package.
Hence, what is needed is a chip package that offers the advantages of stacked chips without the problems described above.